The present invention relates to a structure for mounting an EL (Electro Luminescence) lamp advantageously applicable to a mobile communication apparatus.
Today, the popularization of various kinds of mobile communication apparatuses including handy phones and radio pagers is under way in parallel with the liberalization of electronic and communication environments. A mobile communication apparatus with an LCD (Liquid Crystal Display) is conventional and capable of displaying characters and graphic images. An EL lamp has customarily been used to illuminate the back of the LCD.
It is a common practice with the above mobile communication apparatus to position the EL lamp in an LCD frame or panel frame together with the LCD and then mount the frame to a circuit board. Specifically, the EL lamp includes an electrode portion. Metallic electrode terminals are usually connected at one end to the electrode portion of the EL lamp by anisotropic adhesive by the application of heat and pressure. The adhesive contains a conductive filler dispersed therein. The other ends of the electrode terminals are soldered to the circuit board.
The LCD is produced by dividing an LCD laminate into a number of pieces along scribe lines and therefore sized with a far greater tolerance (about .+-.0.2 mm) than the other parts. It follows that the panel frame is designed in matching relation to the maximum tolerance of the LCD, i.e., the LCD is received in the panel frame with a sufficient dimensional margin. To prevent the LCD from oscillating in the panel frame, the former is usually affixed to the latter together with the EL lamp by two-sided adhesive tapes.
However, the problem with the above conventional structure is that when an impact ascribable to, e.g., a drop acts on the LCD, it is transferred to the EL lamp in the panel frame. Because the EL lamp is simply adhered to the panel frame together with the LCD, the impact causes the electrode terminals to move via the EL lamp. It is therefore likely that the electrode terminals break due to fatigue or come off the EL lamp, obstructing reliable connection both mechanically and electrically.
While Japanese Utility Model Laid-Open Publication No. 5-87890 teaches an EL lamp mounting structure, it cannot solve the problem discussed above.
Technologies relating to the present invention are also disclosed in Japanese Patent Laid-Open Publication Nos. 8-221003 and 9-166673.